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CDK700 Telescope

Our research-grade PlaneWave Instruments CDK700 telescope will inspire those young and young-at-heart for many years to come. This telescope was chosen with the assistance of Mr. Dan McKenna, the then Superintendent of Palomar Mt Observatory, for its quality and versatility. The 27.5″ primary mirror allows us to see millions of light-years away all from the floor of the Coachella Valley. Our telescope even employs a novel solution of placing two refracting telescopes end-to-end to create a periscope for viewing at a comfortable height without the need for stairs. We currently have 3 cameras for imaging the lunar surface, planets, and deep-sky objects. More specifications may be found below, courtesy of PlaneWave Instruments.

“Science progresses best when observations force us to alter our preconceptions.”

Vera Rubin (1928 – 2016), Astronomer

Optical Design Corrected Dall-Kirkham (CDK)
Aperture 700 mm (27.56 inch)
Focal Length 4540 mm
Focal ratio 6.5
Central Obstruction 47% of the Primary Mirror Diameter
Back Focus 309 mm (12.2 inch) from Mounting Surface
Weight 1,200 lbs
Optical Tube Dual truss structure with Nasmyth focus
Optical Performance 1.8 micron RMS spots [25mm on-axis] (400 to 900nm) 4.4 micron RMS spots [21mm off-axis] (400 to 900nm) 6.8 micron RMS spots [35mm off-axis] (400 to 900nm)
Dimensions 93.73″ H x 43.25″ W x 39″ D    
Optimal Field of View 70 mm (0.86 degrees)
Focus Position Nasmyth Focus
Fully Baffled Field 60 mm
Image Scale 22 microns per arcsecond
Fork Assembly Single piece U shaped fork arm assembly for maximum stiffness
Azimuth Bearing 20 inch diameter thrust bearing
Altitude Bearing 2 x 8.5 inch OD ball bearings
Optical Tube Dual truss structure with Nasmyth focus
Motor Control Industrial grade Parker brushless motor control system and built in electronics
Azimuth Motor Direct Drive 3 Phase Axial-Flux Torque Motor
Altitude Motor Direct Drive 3 Phase Axial-Flux Torque Motor
Encoder – Azimuth and Altitude 10 inch disk built into the azimuth and altitude axes with stainless steel encoder tape on the circumference with reader yields 16 million counts per revolution of the telescope. This translates to about 0.08 arcsecond resolution.
Motor Torque Approximately 30 ft-lbs continuous; 60 ft-lbs peak
Drive Electronics Capable of controlling up to 4 high speed encoders, limit switch inputs, homing switch inputs, controls two additional motors for accessories, two brake outputs and 16 digital and 2 analog inputs
Telescope Control Software Incorporates PointXP mount modeling software by Dave Rowe All ASCOM compatible.
Pointing Accuracy 10 arcsecond RMS with PointXP Model
Pointing Precision 2 arcsecond
Tracking Accuracy <1 arcsecond error over 10 minute period
System Natural Frequency 10 Hz or greater
Field De-Rotator Accuracy 3 microns of peak to peak error at 35mm off-axis over 1 hour of tracking (18 arc sec)
Radius of Curvature 4115mm
Optical Diameter 700 mm (27.56 inch)
Outer Diameter 714.38 mm (28.125 inch)
Core Diameter 203mm (8 inch)
Material Fused Silica
Edge Thickness 2.25 inch
Cell 18 point
Radius of curvature 2961 mm
Thickness 25 mm
Optical Diameter 312.4 mm (12.3 inch)
Outer Diameter 317.5 mm (12.5 inch)
Material Fused Silica
Cell 3 point RTV
Optical Major Diameter 152.4 mm
Thickness 25 mm
Material Fused Silica